Owing to the recent development of IT technology, a head mounted display is a rising big issue in everyday life. Particularly, a head mounted display is utilized as a communicating tool for performing essential functions in daily life in association with various programs and applications.
Virtual reality (VR) relates to a technology of providing a reality-like experience through interaction between a virtual space established using a computer and a human sensory system and means a fictional situation or environment rendered using a computer. Herein, the rendered virtual environment or situation stimulates user's sense and enables a user to have a spatial and temporal experience similar to reality, thereby making it look as if happening actually in reality.
If using virtual reality (VR) devices, a user can feel such virtual reality more realistically and be immersed in a virtual reality world by frequently crossing reality and virtual space more easily. As a VR device works as a means for controlling user's motion and experience in such a virtual reality word, since the VR device can interact with targets in the VR world, it is characterized in that each user can have a different experience.
So far, VR devices form small-scale markets in partial fields such as amusement culture (e.g., games, theme parks, etc.) and military computer simulations. Yet, as industry is being developed, the VR technology utilized fields are expanding gradually. VR devices can be utilized across various fields such as archeology, architecture, fine art, music, medical care and the like as well as across well-known fields such as manufacturing business, shopping, military, education and the like.
Particularly, in case of a medical field, as the VR technology is used for metal treatment of PTSD (posttraumatic stress disorder) and the like, the VR related market is possibly regarded as a quickly growing market in the future. Recently, owing to the developments of smartphones, tablets and the like, the general public can experience virtual reality or augmented reality more easily and have decreased repulsion, they are further interested in VR devices.
In VR (virtual reality), there is the concept of ‘presence’ meaning appearance before one's eyes, which means that a user is made to recognize himself as existing in a virtually configured non-physical world by providing a high sense of immersion. In forming such an experience of presence, an obstacle is a delay time (motion to photon latency).
The delay time is a time taken for a photon to arrive at user's eye by reflecting user's motion from a moment of starting the user's motion on a real screen, and means a time difference between a movement of user's eyes and a corresponding screen update. Minimizing the delay time is a decisive factor in providing a convenient VR use environment.
However, since it frequently happens that a delay time is equal to or greater than 20 ms in the related art, as people usually feel dizzy or nausea on running a VR program, there is a problem that a user feels inconvenience.